I. Field of the Invention
The present invention relates generally to valves and, more particularly, to a one-way relief valve for use with a fluid system.
II. Description of the Prior Art
There have been a number of previously known one-way relief valves which have been used with fluid systems and particularly with hydraulic fluid systems. Such relief valves are designed to open at a predetermined pressure in order to permit fluid communication from the inlet of the valve and to its outlet. At all pressures below the predetermined opening pressure, however, the relief valve prohibits fluid communication between its inlet and outlet.
These previous known relief valves typically comprise a valve housing having an inlet and an outlet. A conventional fluid fitting is connected to the inlet while a similar fitting is connected to the outlet for connection with cooperating fluid connectors on the fluid system. This previously known construction, however, is disadvantageous in that the relief valve housing, typically a casting, is very expensive to fabricate. Thus, the housing with its fluid fittings significantly increases the overall cost for the relief valve. p A further disadvantage of these previously known relief valves having an opening pressure up to about 100 psi is that the opening pressure for such relief valves is commonly preset and nonadjustable. Consequently, it is either necessary to maintain an entire line of relief valves with different opening pressures in order to accommodate the different requirements for fluid systems or to incorporate costly adjustment means.
Many of these previously known relief valves included a valve member which is resiliently urged towards a closed position against a valve seat and opens only when the pressure on the valve member exceeds a predetermined amount. However, during pressure surges in the fluid system which are sufficient to open the relief valve, the valve member can become cocked within its housing which can jam the relief valve in an open position. Once the relief valve is stuck or jammed in its open position, disassembly of the relief valve is usually required in order to repair or unjam the valve member.